The main goal of this proposal is to develop a novel method of fragmentation of biomolecules in an electrospray ionization (ESI) quadrupole/time-of-flight mass spectrometer (Q-TOF MS). The new method will enable many more bonds to cleave than a conventional collisionally activated dissociation. It also will preserve labile modifications of the amino acid side chains, such as phosphorylation and glycosylation that facilitates determination of their sites, and can also distinguish between Leucine and Isoleucine amino acid residues. Combined with liquid separation techniques (HPLC,CE) Q-TOF mass spectrometer with a new fragmentation method will provide high-throughput analysis of protein mixtures. [unreadable] [unreadable]